6-methyl-3-oxo-4:6-dienic steroids



United States Patent Cfifiice Patented Nov. 6, 1962 This invention is for improvements in or relating to organic compounds and has particular reference to the preparation of new 6-methyl-3-oxol:6-dienic steroids.

It is an object of the present invention to provide new 6-methyl-3-oxo-4:6-dienic steroids which are of value on account of their biological properties or as intermediates in the preparation of other 6-methylated compounds with useful biological properties, such, for example, as 6- methylandrostanolone.

We have made the surprising discovery that the 6-methyl-6-dehydro derivatives of 3-oxo-A -steroid hormones may be more active hormonally than the 3-0xo- 4:6-dienic derivatives of androstane and pregnane and more active even than the corresponding 3-oxo-A -steroid hormones.

Thus, for example, we have found that the 6-rnethyl-6- dehydro derivative of ethisterone when administered by the oral route is approximately twice as potent a progestational agent as is ethisterone itself.

The 6-methyl-3-oxo-4:6-dienic derivatives (1) of androstane and pregnane obtained by the process of the invention may be regarded as the '6-dehydroderivatives of 3-oxo-6-methyl-A -steroids, into which we find they may be converted by hydrogenation. The 3-oxo-6- methyl-M- derivatives of androstane and pregnane, as is well known to those skilled in the art, are of importance on account of their biological properties.

According to the present invention there are provided 6-methyl-3-oxo-4:6-dienic steroids of the androstane and pregnane series having the general formula The invention also provides the specific new compounds 6-methylandrosta-4:6-diene-3:l7-dione which is a dehydroderivative of 6-methyl androstenedione, and is of value as an intermediate in, for example, the preparation of 6-methyl-6-dehydrotestosterone.

l7fi-hydroxy-6: 17oc-dl1'I16lZhYlfiI1dI0Si21 4:6 dien-3-one, which is the dehydro-derivative of 6a:17o-dimethyltestosterone, and has anabolic properties.

17fl-hydroxy-17a-ethynyl 6 methylandrosta-4:6-dien- 3-one which is the dehydro-derivative of 6a-methyl-ethisterone and is a potent orally acting progestational agent.

6-methylpregna-4:6-diene-3:ZG-dione, which is a dehydro-derivative of 6a-rnethylprogesterone, is a progestational agent and is a valuable starting material for the preparation of the surprisingly potent 6-methyl derivatives of dehydrohydrocorti'sone.

The invention further provides a method for the preparation of 6-methyl-3-oxo-4:6-dienic steroids of the androstane and pregnane series having the general formula I above which method comprises reacting the correspond- 2 ing Bfi-hydroxy or 3 8-acyloxy-5a-hydroxy-6-cxo-steroid having the general formula 0 (II) where R=H or acyl with a methylmagnesium halide to give a 6-methyl-3fl:5a:6-trihydroxy steroid having the general formula Me i a??? 1 OH Me (III) oxidising the 3ez5otz6-trihydroxy steroid to the corresponding 5a:6-dihydroxy-6-methyl-3-oxo-steroid having the general formula O Me (IV) and dehydrating the 5a: 6-dihydroxy-6-methyl-3-oxosteroid. t

The 3,8-acyloxy or 3,8-hydroxy-5a-hydroxy-6oxo-ste roids which constitute the starting materials of the above mentioned process may be obtained by a variety of methods, such as, for example, by oxidation of the corresponding 3,8-acyloxy-5az'6l3-dihydroxy steroids which in turn may be derived from 3/3-acyloxy-5z6-epoxy steroids by hydrolytic epoxide ring fission. Such transformations are well known to those skilled in the art, and have been adequately described in the literature. See Heusler and Wettstein, Helv. Chim. Acta, 1952, 35, 284.

In carrying the process of the invention into effect, the conversion of the 3fl-acyloxy or 3fi-hydroxy-5a-hydroxy- 6-oxo steroid (II) into the 6-nethyl-3fl:5az6-trihydroxy steroid (III) is conveniently. achieved by adding a solution of the compound (II) (R=H or acyl) in .a solvent such as ether or butyl ether, or a mixture of benzene and ether to an excess of methyl magnesium halide, prefer ably the bromide or iodide, and refluxing the mixture or allowing the mixture to stand at room temperature for several hours. Thereafter, the complex formed is decomposed and the steroidal product extracted. The 6-methyl- 3fiz5az6-trihydroxy steroid (Ill) so obtained may be admixed with its 3,6-acyloxy-derivative in amounts which are determined by the particular conditions and time employed for the Grignard reaction. It is, therefore, advisable to saponify the total product of the reaction in order to convert the admixed 3/3-acy1oxy-5a:6-dihydroxy-6- methyl steroid into the required 6-methyl-3,8:5a:6-trihy 'droxy steroid (III).

The conversion of the 6-methyl-3 8:5a:6-trihydroxy steroid (III) into the corresponding 3-oxo steroid (IV) may be accomplished by the use of oxidants commonly used for the transformation of a secondary alcohol into the corresponding ketone. Thus, chromium trioxide in acetic acid, or chromium trioxide in pyridine solution are suitable reagents, the particular oxidant employed, however, being determined by the nature of any substituents which may be additionally present in the 6-methyl-3,B: 5at6-trihydroXy steroid (III).

Dehydration of the 3-oxo-steroid (IV) to the required 6-methyl-3-oxo-4:6-diene derivative (I) may be effected by treating compound (IV) in a solvent with a source of hydrogen ions, which is, conveniently, hydrogen chloride. The transformation may be achieved, for example, by passing hydrogen chloride into a solution of the 3-oxosteroid (IV) at temperatures in the region of C. Alternatively, for example, a solution of the 3-oxo steroid (IV) in a lower aliphatic alcohol containing up to five carbon atoms, such as methanol, or ethanol, to which a trace of concentrated hydrochloric acid has been added, may be heated at the reflux temperature when dehydration readily occurs.

The process of the invention may be applied to 313- acyloxy or 3fi-hydroxy-5e-hydroxy-6-oxo steroids belonging to the androstane and pregnane classes. Thus, the process of the invention may be applied to the following: Sfl-acyloxy-Se-hydroxyandrostan-6-one which may be additionally substituted at C by hydroxyl with or without alkyl, alkenyl or alkynyl groups containing not more than 5 carbon atoms, 3 3-acyloxy-Su-hydroxypregnan-6-one which may be additionally substituted by an acyloxy or hydroxy group at C with or without acyloxy or alkyl groups containing not more than 5 carbon atoms at C or C Following is a description by way of example of methods of carrying the invention into effect:

' "c5011 ltie 3 3 acetoxy 17a ethynylandrostane 511:175 diol- 6-one (M.P. 245 to 247 C., [041 -103 in chloroform) (10.5 g.), prepared by applying the standard method of Heusler and Wettstein (Helv. Chim. Acta, 1952, 35, 284), to the corresponding 3 8-acyloxy 5:6-epoxy compound, in

a mixture of dry tetrahydrofuran (100 ml.) and ether (100 ml.) was added to a Grignard reagent prepared from magnesium (5.4 g.), methyl iodide ml.) and ether (190 ml.). The mixture was stirred at room temperature for 2 hours, and then allowed to stand for a further 18 hours. After treatment with dilute sulphuric acid, the organic layer was washed until neutral, dried, and the solvents removed. The residue was heated under reflux for minutes with methanolic potassium hydroxide (100 ml. of 2%). The product obtained by adding water was crystallised from aqueous methanol to give 17a-ethynyl- 6-methylandrostane-3fi25a:6:17,8-tetrol, needles, M.P. 254 to 255 C., [a] --5l (c. 1.01 in ethanol).

The foregoing tetrol (4 g.) in pyridine ml.) Was added to a solution of chromium trioxide (4 g.) in pyridine (40 ml.) and the mixture allowed to stand overnight. The

4 product was isolated with ether and crystallised from aqueous ethanol. 17a-ethynyl-6-methylandrostane-5az 6:17fi-triol-3-one formed needles, M.P. 246 to 248 C., ---36 (c. 1.02 in ethanol).

The foregoing compound (1 g.) in ethanol (25 ml.) containing two drops of concentrated hydrochloric acid was heated under reflux for 30 minutes. The product was isolated with ether and crystallised from equous methanol. 17a-ethynyl-17fl-hydroxy 6 methylandrosta- 4:6-dien-3-one formed needles, M.P. 200 to 201 C., [a] -58 ('c. 1.03 in chloroform), k 290 my (log 5:4.36').

EXAMPLE 2 6 -M ethylpregna-4:6 -D ienc-3 :2 O-Dione (VI) 3,8:ZO-diacetoxypregnan-Sa-ol-6-one (M.P. 224 to 225 C., [ch 48 in chloroform) (4.3 g.), prepared by applying the standard method of Heusler and Wettstein (Helv. Chim. Acta, 1952, 35, 284), to the corresponding 3;.3-acyloxy 5 :6-epoxy compound, in benzene (200 ml.) was added with stirring to a solution of methyimagnesium iodide prepared from magnesium (4.3 g.) and methyl iodide (12 ml.) in dry ether ml.). The mixture was heated under reflux for 3 hours, cooled, and treated with ice-cold aqueous ammonium chloride. The solids obtained were crystallised from acetone/hexane, giving 6 methylpregnane-3flz5az6:20-tetrol, needles, M.P. 220 to 224 C., [111 17 (c. 0.24 in chloroform).

The foregoing tetrol (1.5 g.) in pyridine (15 ml.) was added to chromium trioxide (3 g.) in pyridine (30 ml.) and the mixture allowed to stand overnight. It was then filtered through a filter-aid and the solids washed with hot benzene (600 ml.). The combined filtrate and washings were washed in turn with dilute hydrochloric acid, aqueous sodium carbonate and water, then dried and passed through a short column of alumina. Elution with ether gave 6-methylpregnane-5a:6-diol-3:20-dione, which crystallised from acetone/hexane in needles, M.P. 247 to 249 C., [M +69 (c. 0.39 in chloroform).

The foregoing compound (300 mg.) in methanol (50 ml.) containing two drops of concentrated hydrochloric acid was heated under reflux for 30 minutes. The mixture was poured into a relatively large volume of water, and the precipitated solids collected, washed and dried. crystallisation from hexane gave 6-methylpregna-4z6- diene-3:20-dione, plates, M.P. 152 to 154 C., [M +176 (c. 0.56 in chloroform), A 288.5 m (log e=4.37).

EXAMPLE 3 6 :1 7a-Dim ethyl-1 7 5-11 y droxyan d rosta- 4:6-Dien-3-One (VII) (VII 313 acetoxy 51121713 dihydroxy 17a methylandrostan-6-one (M.P. 207 to 208 C., 98 in chloroform) (6.5 g.), prepared by applying the standard method of Heusler and Wettstein (Helv. Chirn. Acta, 1952, 35, 284), to the corresponding 3 fl-acyloxy 5:6-epoxy compound, in ether (300 ml.) was added to a Grignard reagent prepared from magnesium (6.5 g.) and methyl iodide (42 g.) in a mixture of ether (300 ml.) and benzene (200 ml.). The mixture was heated under reflux for 3 /2 hours, cooled, treated with aqueous ammonium chloride, and the solid product collected and washed. It was saponifled by heating under reflux for 1 hour with potassium carbonate (4 g.) in methanol (180 ml.) and Water ml.). The solvents were removedand the residue extracted with hot acetone. Addition of hexane gave 6: 17a-dimethylandrostane-3 8:5 04:6: 17B-tetrol, needles, M.P. 233 to 234 C., 24 (c. 0.55 in etha- 1101).

The foregoing tetrol (1.8 g.) in pyridine (18 ml.) was added to a solution of chromium trioxide (1.8 g.) in pyridine (18 m1.) and the mixture allowed to stand overnight. The product, isolated with benzene, was crystallised from acetone/hexane, giving 6: 17oz dimethylandrostane 5a: 6:17B-triol-3-one, needles, M.P. 223 to 224 C., (c. 0.53 in chloroform).

The foregoing compound (1.85 g.) in methanol (20 ml.) containing concentrated hydrochloric acid (0.3 ml.) was heated under reflux for 1 hour. The product, isolated with ether, was purified from acetone/hexane to give 6: 17a-dimethyl-l7fi-hydroxyandrosta-4 6-dien-3-one, M.P. 157 to 158 C., [041 +38 (c. 0.52 in chloroform), A 290 mp. (log 6:4.37).

O (VIII) :17fi-diacetoxy-5a-hydroxyandrostan 6 one (4 g.), prepared by the standard method of Heusler and Wettstein (Helv. Chirn. Acta, 1952, 35, 284), in benzene (250 ml.) was added to a Grignard reagent prepared from magnesium (4 g.) and methyl iodide (25 ml.) in ether (50 ml.). The mixture was heated under reflux for 2 hours, cooled, and treated with aqueous ammonium chloride. The solids obtained were saponifi-ed with aqueous methanolic potassium carbonate to give 6-methylandrostane- 3pz5azzl7fl-tetrol, which crystallised from acetone in needles, M.P. 195 to 205 C. softens, [041 24 (c. 0.25 in ethanol).

The foregoing compound (3.3 g.) in pyridine (33 ml.) was added to a solution of chromium trioxide (6.6 g.) in pyridine (66 m1.), and the mixture allowed to stand overnight. The product was isolated with benzene, puri fied chromatographically, and crystallised from aqueous acetone. 5x26 dihydroxy-6-methylandrostane-3:17-dione formed needles, M.P. 242 to 244 C., [111 +65 (c. 0.57 in chloroform).

The foregoing compound (0.5 g.) in methanol (20 ml.) containing two drops of concentrated hydrochloric acid was heated under reflux for 1 hour. The solid obtained on the addition of water was washed, dried, and crystallised from acetone/hexane. 6-methylandrosta-4 6-diene-3 17- dione separated in needles, M.P. 164 C., [a] +139 (c. 0.51 in chloroform), A 287 mp (log e=4.37).

We claim:

1. 6-methylandrosta-4 6-diene-3: 17-dione.

2. 17B-hydroxy-17ot-ethynyl-6-methylandrosta-4:6-dien- 3-one.

3. 17a ethynyl6-methylandrostane-313:5u:6:17fi-tetrol, M.P. 254 to 255 C., -51 (c. 1.01 in ethanol).

4. 17ot-ethynyl-6-methylandrostane-5u 6: 17fl-triol-3-one, M.P. 246 to 248 C., [M ---36 (c. 1.02 in ethanol).

5. 6-methylpregnane-3/3z5az6:20-tetrol, M.P. 220 to 224 C., [M 17 (c. 0.24 in chloroform).

' 6. G-methyIpregnane-Sa:6-diol-3:20-dione, M.P. 247 to 249 C., [0:] +69 (c. 0.39 in chloroform).

7. 6 17a-dimethylandrostane-3 3 5 oz 6 17fl-tetrol, 233 to 234 C., [a] -24 (c. 0.55 in ethanol).

8. 62170; dimethylandrostane 511262175 triol 3- one, M.P. 223 to 224 C., 5 25 (0. 0.53 in chloroform).

. 9. 6-methylandrostane-5a:6-diol-3:17-dione, M.P. 242 to 244 C., [ad |6S (c. 0.57 in chloroform).

10. A method for the preparation of 6-methyl-3-oxo- 4:6-dienic steroids of the androstane and pregnane series, comprising: reacting the corresponding 3,8-acyloxy-5ahydroxy-6-oxo steroid having in rings A and B the following structure:

(where R is a lower alkanoyl radical) with a methyl magnesium halide to give a corresponding 6-methyl-3fi:5 x:6- trihydroxy steroid having in rings A and B the following structure:

oxidizing the 3,825 az6-trihydroxy steroid to the correspondmg 5a:6-dihydroxy-6-methyl-3oxo steroid having in rings A and B the following structure:

11. A method as claimed in claim 10 wherein a solution of the 3fl-alkanoyloxy-Sa-hydroxy-S-oxo steroid in a solvent is added to an excess of methyl magnesium iodide.

12. A method as claimed in claim 10 wherein the 3/3:5a:6-trihydroxy steroid is oxidised to the correspond ing 5a:6-dihydroxy-6-methyl-3oxo-steroid with chromium trioxide in pyridine solution.

13. The method of claim 10 wherein the 3/3-acyloxy-5ahydroxy-6-oxo steroid starting material is 3fl-acetoxy-17aethynyIandrOstane-Sa:l7 3-diol-6-one, the reaction with methyl magnesium halide provides 17a-ethynyl-6-methy1- androstane-3fiz5az6:17p-tetrol, the tetrol is oxidized to provide 17a-ethynyl-6-methylandrostane-5on6:17B-triol-3-one and the latter compound is dehydrated to provide ethynyl-17/3-hydroxy-6rnethylandrosta-4:6-dien-3-one.

14. The method of claim 10 wherein the 3 ,8-acyloxy-5 ahydroxy-6-oxo steroid starting material is 33:20-diacetoxypregnan-5a-o1-6-one, the reaction with methyl magnesium halide provides 6-methylpregnane-3fiz5az6:20-tetrol, the tetrol is oxidized to provide 6-rnethylpregnane-5a:6-dio1 3:2Q-dione and the latter compound is dehydrated to provide 6 -methylpregna-4:6-diene-3:2 O-dione.

15 The method of claim 10 wherein the 3fl-acy1o ry-5uhydroxy-6-oxo steroid starting material is BfiaicetoXy- 5a:17p-dihydroxy-17q-methylandrostan-6-one, the reaction with methyl magnesiumhalide provides 6: l7a-dimethylandrostane-3pz5az6 i17fi-tetrol, the te-trol is oxidized to provide 6:17a dimethylandrostane 5 u6zl7fl-triol 3-one and the latter compound is dehydrated to provide 6:17adirnethyl-l7fl-hydroxyandrosta-4:6-dien-3-one.

16 The method of claim 10 wherein the SQ-acyloxy-Sahydroxy-doxo steroid starting material is 3fiz'l 7fl-diacetoxy-5-hydroxyandrostan-6-one, the reaction with methyl magnesium halide provides 6-methylandrostane' 3fiz5oiz6zl7fi-tetrol, the latter compound is oxidized to 50;:6-dihydroxy-6-n1ethylandrostane 3:l7-dione and the latter compound is dehydrated to provide 6-methylandrosta-4z6-diene-3z17-diorie,

2,312,344- Logemann Mar. 2, 1943 2,738,348 Colton Mar. 13, 1956 2,739,974 Colton Mar. 27, 1956 3,002,969 Petrow et al. Oct. 3, 1961 3,004,966 Petrow et a1. Oct. 17, 1961 OTHER REFERENCES Journal of Organic Chemistry (1954), vol. 19, article by 15 Florey, pages 1331-50., 

1. 6-METHYLANDROSTA-4:6-DIENE-3:17-DIONE.
 6. 6-METHYLPREGNANE-5A:6-DIOL-3:20-DIONE, M.P.247 TO 249*C., (A)D22+69* (C. 0.39 IN CHLOROFORM). 